Toluene → 4-(acetoxymethyl)-2-[(E)-2-[4-(trifluoromethyl)phenyl]ethenyl]-1,3-oxazole

Temperatur

72.5 °C

(E)-3-(4-(Trifluoromethyl)phenyl)-2-propenamide (10.0 g,46.5 mmol) and 1,3-dichloroacetone (11.0 g, 86.6 mmol) were added to toluene (50 ml), and the mixture was subjected to refluxing azeotropic dehydration using a Dean-Stark tube for 8.5 hours. The reaction mixture was concentrated under reduced pressure. To the residue were added dimethyl sulfoxide (50 ml) and sodium acetate trihydrate (15.8 g, 116.1 mmol). The mixture was stirred at 70-75° C. for 4 hours. Methanol (50 ml) was added. After allowing-to cool to room temperature and stirring; the mixture was stirred under ice-cooling for 1 hour. The precipitated crystals were collected by filtration, washed with cold-methanol (30 ml) and dried under reduced pressure to give 4-(acetoxymethyl)-2-[(E)-2-[4-(trifluoromethyl)phenyl]ethenyl]-1,3-oxazole (13.1 g, yield 65%).

1. temperatureto refluxing azeotropic dehydration
2. customfor 8.5 hours
3. concentrationThe reaction mixture was concentrated under reduced pressure
4. temperatureAfter allowing-to cool to room temperature
5. stirringstirring
6. stirringthe mixture was stirred under ice-
7. temperaturecooling for 1 hour
8. filtrationThe precipitated crystals were collected by filtration
9. washwashed with cold-methanol (30 ml)
10. customdried under reduced pressure

ORD-Eintrag

ord-6c7a09e552c3430f98ac75e781c5f0fa

Quelldatensatz

uspto-grants-2004_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06743924B2